Hot cup



Dec. 3, 1940. F. M. CARATHERS HOT CUP Filed May 3, 1939 ATTORNEY-5':

Patented Dec. 3, 1940 UNITED STATES HOT CUP Floyd M. Carathera, Chicago,Ill., assignor to Lacy Products Corp., Chicago, Ill., a corporation ofIllinois Application May 3, 1939, Serial No. 271,534

Claims.

The present invention relates to a heating or warming device and moreparticularly to a construction known as a hot cup and employed atso-called beverage dispensing fountains for the preparation of warmbeverages and hot mixed drinks.

The present invention relates yet more particularly to an improved hotcup which is permanent, rigid and serviceable, but which may be readilymanipulated for disassembly and repair. Hot cup constructions in generalcomprise an inner and outer shell providing therebetween an annularspace accommodating a heating element, together with a, thermostaticcontrol, where such a control is desired. In the past many expedientshave been availed to assure the structural interassembly of the twoshells. Many of the prior constructions failed to withstand theconditions of service including the jars and impacts to which thepresent device is normally subjected particularly adjacent the upper rimportion.

Hot cup constructions are necessarily and preferably so assembled as toseal the internal space for preventing the access of moisture theretoduring washing. As a result when due to the inadvertent or accidentaloperation of the device overheating occurs, a pressure may be built upin the internal space and such pressures have been known to cause anexplosion. By employing hitherto known constructions wherein theindividual shells are forced together under pressure as by means of apress fit," or by otherwise forcing the metal of the shells into firmengagement by metal bending and shaping operations, the danger ofserious explosion is obviously increased. Periodic repair and inspectionis additionally rendered difficult with these devices since it isnormally quite impossible to expeditiously separate the parts so joined,necessitating the cutting apart of the shells adjacent their point ofjuncture.

It is an important object of the present invention to obviate the abovedifliculties by providing a hot cup construction in which the shells arefreely interengaged during assembly, which construction may accordinglybe relatively readily and freely separated for repair purposes. Moreparticularly, the present invention contemplates a hot cup constructionwherein the inner and outer shells are associated mechanically with eachother during assembly by means of a simple free lit, the inner cuphaving wall portions parallel with the outer cup providing coextensivemutually supporting wall portions, both terminating in an interlockingengagement at the upper rim or edge portion of the hot cup to provide astrong, rigid, shock-resistant reenforcement at this point.

It is a further object of the present invention to provide aconstruction as above wherein the interengaging rim portions are freelyseparable at the time of assembly, but providing a suitable recess for abody of welding or sealing material such as solder. In accordance withthe present improved construction, the mere softening of the solderpermits free separation of the shells and in the event of inadvertentoverheating, abnormal internal pressures are freely relieved through thespace between the coextensive shell portions.

Numerous other objects and advantages will be apparent throughout theprogress of the fol- 0 lowing specification.

The accompanying drawing illustrates a selected embodiment of theinvention and the views therein are as follows:

Fig. 1 is a perspective view of a hot cup embodying the principles ofthe present invention.

Fig. 2 is a sectional view taken centrally through the hot cup of Fig. 1along the line 2-2 of Fig. 1.

Fig. 3 is a detailed sectional view of the rim construction taken alongthe line 3-2 of Fig. 2.

Fig. 4 is a detailed view taken centrally through a spinning die,showing a hot cup shell in place therein, illustrating the method offormation of the upper rim portion thereof.

Fig. 5 is a detailed sectional view taken along the line 5-5 in Fig. 2and illustrating the thermostatic construction.

The hot cup shown herein for the purpose of illustrating the presentinvention comprises an outer shell l0 and an inner shell I2, the twoshells being coaxially arranged in assembled position. Upon the surfaceof the outer shell are aflixed a pair of brackets H which mount apreferably heat insulating handle portion l6 and a guard plate or walll8 to protect the hand against contact with the heated surfaces of thecup. Upon the opposite surface of the outer shell is mounted a socketfitting 20 arranged within a suitable opening bounded by flange 22.

The fitting comprises a pair of prongs 24 adapted to receive a suitableelectric plug for current supply to an electrical heating element 28embracing the lower portion of the inner shell I2.

A thermostatic control element 28 mounted on the bottom surface of theinner shell I! by means of a bracket 30, comprises an insulating block32 upon which is supported a fixed but adjustable contact 34 and amovable contact 38 mounted 5 upon a bimetallic strip 38. It will beunderstood that at a predetermined temperature the bimetallic strip 38moves away from contact 34 to break the circuit to the heating element26, thus limiting the temperature of the contents of the cup to apredetermined value.

It is particularly important to note as clearly shown in Figs. 2 and 3that the circular wall of the outer shell I0 is slightly tapered andterminates upwardly in a substantially undeformed edge 40. The innershell 12, while being of sub stantially reduced diameter adjacent itslower portions to accommodate the heating element 26 flares outwardly asat 42 and upon approaching the upper edge 40 of the outer shell, residesin parallel relationship with the coaxial wall of the outer shell as at44. It is of particular significance to note that these wall sectionswhile being in parallel coextensive relationship, are nevertheless soformed that they slide freely upon one another into assembled position.This is accomplished by carefully preforming the shells to a dimensionsuch that ample clearance is provided.

Such a dimension may be of the order to provide a clearance of tenone-thousandths 95000) of an inch between parallel wall portions. Itmust be remembered that according to prior known constructions ingeneral use, the practice has been to interengage the inner and outershells by what is known to the art as a force or driving fit followed bysoldering which rendered it impractical to separate the shells withoutdamage and sometimes resulted in the violent release of pressures underexplosive conditions. It may be stated that the present interassociationof the 40 shells is characterized by a free or sliding flt.

It should be further particularly noted that the inner shell 12terminates at its upper edge in a reversely extending flange portion 46which in assembled relationship completely embraces 45 the upper edge 40of the outer shell- I0. It has been found in accordance with the presentinvention that the clearance provided between the inner surface of theflange 46 and the outer adjacent surface of the shell I0 must be amplysufficient to permit perfectly free interengagement while permittingstructural cooperation of the parts in reenforcing relationship as willhereinafter more fully appear. As much as thirty one-thousandths %000)of an inch clearance at 65 this point has been found to result in asatisfactory construction.

After the interassembly of the parts as shown in Figs. 1, 2 and 3, theresidual space within the recess formed by the reversely extendingflange 60 46 is filled with solder 48. It will be understood that thismay be accomplished in any conventional manner, as for example by firsttinning the adjacent surfaces and then dipping the upper edge into amolten bath of solder.

65 The resulting construction provides a hot cup in which the two shellsare firmly and permanently interjoined and sealed together and whichprovides a strongly reenforced upper edge or rim portion which isnevertheless non-protrusive and neat in appearance. It is believedimportant to note that in spite of the substantial clearance providedbetween the adjacent shell surfaces, the metal of the two shellscooperates in resisting structural deformation. Thus while it isrealized 75 that solders are normally relatively soft, the arrangementof the present sealing metal in relatively thin sections and embracedupon all sides by the rigid metal of the shells effectively supports andcombines the rims of the inner and outer shells into a reenforcedconstruction of improved structural properties.

The coextensive wall portions 44 of the inner shell residing adjacentthe parallel coextensive wall portions of the outer shell l0 similarlycooperate to brace and mechanically interengage 10 the parts againstdeformation or separation. In other words, these wall sections whileproviding a free fit are nevertheless for all practical purposesarranged in contiguous juxtaposition. In accordance with the presentinvention, it has 15 been discovered where the wall surface 44 is not soarranged in contiguous parallel relationship to the outer adjacent wall,the point of juncture is markedly weakened to a degree seriouslyaffecting the serviceability of the finished article. 20

It may sometimes occur as stated above that the device may be subject tooverheating and the creation of an abnormal pressure due to carelessoperation, to a failure of the control device, or due to the inattentionof the operator when em- 25 ploying a unit of the type which is notprovided with a thermostatic control, to which type of hot cupconstruction the present invention is likewise applicable. Under suchcircumstances, it will be evident from the foregoing that the 0 body offusible metal at the point 48 will fuse or soften so that the internalpressure will be relieved at a moderate temperature. Should anysubstantial pressure exist within the internal space, the inner cup Illwill freely move upward- 1y a short distance while the compressed gasesare progressively relieved through the clearance space between theparallel sections of the shells.

It will be obvious from the foregoing that the present constructiondemands careful preformation of the inner shell, and to this end I haveprovided for the formation of the reversely extending flange 46 throughthe medium of a simple spinning operation involving a spinning die orform such as shown in Fig. 4. The shell, preferably previously shaped,is placed within the central recess in the form 50 and the projectingedge spun or formed over rim portion 52 of the die as indicated by thedotted lines in Fig. 4. Upon withdrawal from the die the inner shell 50will have a rim configuration disclosed in Figs. 2 and 3, formed withinpredetermined tolerances.

It will be understood that the fabrication of the inner shell by meansof a spinning step is disclosed for illustrative purposes only and thatthe 55 invention is not so limited, but comprehends the assembly ofparts in accordance with the present invention, however they are shapedor derived.

The present invention provides a hot cup invention which is extremelysimple, but which ob- 6O viates all of the defects hitherto encountered.

It is understood that the figures of the drawing, do not purport toaccurately represent the relative dimensions of the parts. Theclearances involved, for example, are so minor that it would 5 beimpractical to specifically represent them upon a drawing of this kindand it is, accordingly, the purpose of the present drawing to illustratethe relation of the parts in more or less exaggerated form.

Changes may be made in the form, construction and arrangement of theparts without departing from the spirit of the invention or sacrificingany of its advantages, and the right is hereby reserved to make all suchchanges as 76 fairly fall within the scope of the following claims.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is as follows:

1. A self-heating hot cup construction for warming beverages comprisingan outer shell and an inner shell, said inner shell having an upstandingside wall projecting to the upper rim of the cup and being reverselybent at said margin to provide a flange substantially parallel to saidside wall and spaced therefrom a predetermined distance to provide anaxially, downwardly opening recess, an outer shell co-axially receivingsaid inner shell and having an annular side wall substantially parallelto and co-extensive with said annular wall of the inner shell over asubstantial axial extent but spaced therefrom a predetermined distanceby a substantial clearance providing a passage of substantial lateraldimension permitting free axial separation of the shells, said outerwall extending to said rim and having its upper marginal peripheryreceived within said recess, said upper margin being spaced from saidflange by a predetermined lateral clearance providing a. passageoperative to permit free axial separation of the margin from the recess,and a fusible sealing material within the recess and sealing the passagebetween the inner and outer shells, said walls being tapered downwardly.

2. A self-heating hot cup construction for warming beverages comprisingan outer shell and an inner shell, said outer shell comprising anannular wall portion being substantially straight in an axial directionand terminating in a free upper edge at the upper rim of the cup, saidinner shell having an upper annular wall portion arranged interiorly ofsaid first-mentioned annular wall and extending in parallel relationshiptherewith over a substantial axial distance to provide a freelyseparable sliding fit, the extremity of said inner wall being flanged toprovide a reversely axially extending flange parallel to both of saidwall portions and spaced from said uter wall portion to freely receivethe said edge of the outer wall within the recess formed by said flange,and a body of solder material within said recess and sealing said edgestogether.

3. In a self-heating hot cup comprising an inner and outer shellproviding an intermediate chamber for accommodating a heating element,the outer shell having an upstanding side wall of substantial verticalextent extending in a straight line to the upper marginal rim, the irmershell having an upper wall comprising a side wall received within saidfirst named side wall and being parallel and coextensive therewith overa substantial axial distance, said inner shell having a flanged rim atits upper margin bent reversely to enclose the outer shell rim, saidflange extending downwardly substantially parallel to both of said sidewalls in spaced relation thereto, said walls and said flange havingsubstantial lateral clearances providing passages of substantial widthbetween the inner and outer shell and between the outer shell and saidflange for free axial separation of the inner and outer shells, and lowmelting sealing material in said clearance spaces and sealingly engagingthe walls and the flange.

4. In a. self-heating hot cup comprising an inner and outer shellproviding an intermediate chamber for accommodating a heating element,the outer shell having an upstanding side wall of substantial verticalextent extending in a straight line to the upper marginal rim, the innershell having an upper wall comprising a side wall received within saidfirst named side wall and being parallel and coextensive therewith overa substantial axial distance, said inner shell having a flanged rim atthe upper margin bent reversely to enclose the outer shell rim, saidflange extending downwardly substantially parallel to both of said sidewalls in spaced relation thereto, said walls and said flange havingsubstantial lateral clearances providing passages of substantial widthbetween the inner and outer shell and between the outer shell and saidflange for free axial separation of the inner and outer shells.

5. In a self-heating hot cup construction for warming beveragescomprising an outer shell and inner shell coaxially disposed and spacedad- Jacent their lower portions to accommodate an electrical heatingelement therebetween; said inner shell having an upstanding side wallprojecting to the upper rim or the cup and being reversely bent at saidrim to provide a flange substantially parallel to said side wall and spoutwardly therefrom a predetermined distance to provide a downwardlyopening recess, the outer shell coaxially receiving said inner shell andhaving an annular side wall residing in relatively close juxtapositionto said inner wall above said lower portions, said last named wallsbeing substantially parallel and coextensive over a substantial axialextent but being laterally spaced by sunlcient clearance to provide apermanent passageway, said outer wall having its upper peripheryreceived within said recess and being spaced from said flange by asubstantial clearance providing a permanent passageway and operative topermit free passage of gaseous fluid, and fusible sealing materialwithin the recess and sealing at least one of said passages between theinner and outer shells.

FLOYD M. CARATHERS.

